Remove commented-out debug #define cruft
[ffmpeg.git] / libavcodec / h263dec.c
1 /*
2  * H.263 decoder
3  * Copyright (c) 2001 Fabrice Bellard
4  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
5  *
6  * This file is part of Libav.
7  *
8  * Libav is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * Libav is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with Libav; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22
23 /**
24  * @file
25  * H.263 decoder.
26  */
27
28 #include "libavutil/cpu.h"
29 #include "internal.h"
30 #include "avcodec.h"
31 #include "error_resilience.h"
32 #include "mpegvideo.h"
33 #include "h263.h"
34 #include "h263_parser.h"
35 #include "mpeg4video_parser.h"
36 #include "msmpeg4.h"
37 #include "vdpau_internal.h"
38 #include "thread.h"
39 #include "flv.h"
40 #include "mpeg4video.h"
41
42 av_cold int ff_h263_decode_init(AVCodecContext *avctx)
43 {
44     MpegEncContext *s = avctx->priv_data;
45
46     s->avctx = avctx;
47     s->out_format = FMT_H263;
48
49     s->width  = avctx->coded_width;
50     s->height = avctx->coded_height;
51     s->workaround_bugs= avctx->workaround_bugs;
52
53     // set defaults
54     ff_MPV_decode_defaults(s);
55     s->quant_precision=5;
56     s->decode_mb= ff_h263_decode_mb;
57     s->low_delay= 1;
58     if (avctx->codec->id == AV_CODEC_ID_MSS2)
59         avctx->pix_fmt = AV_PIX_FMT_YUV420P;
60     else
61         avctx->pix_fmt = avctx->get_format(avctx, avctx->codec->pix_fmts);
62     s->unrestricted_mv= 1;
63
64     /* select sub codec */
65     switch(avctx->codec->id) {
66     case AV_CODEC_ID_H263:
67         s->unrestricted_mv= 0;
68         avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
69         break;
70     case AV_CODEC_ID_MPEG4:
71         break;
72     case AV_CODEC_ID_MSMPEG4V1:
73         s->h263_pred = 1;
74         s->msmpeg4_version=1;
75         break;
76     case AV_CODEC_ID_MSMPEG4V2:
77         s->h263_pred = 1;
78         s->msmpeg4_version=2;
79         break;
80     case AV_CODEC_ID_MSMPEG4V3:
81         s->h263_pred = 1;
82         s->msmpeg4_version=3;
83         break;
84     case AV_CODEC_ID_WMV1:
85         s->h263_pred = 1;
86         s->msmpeg4_version=4;
87         break;
88     case AV_CODEC_ID_WMV2:
89         s->h263_pred = 1;
90         s->msmpeg4_version=5;
91         break;
92     case AV_CODEC_ID_VC1:
93     case AV_CODEC_ID_WMV3:
94     case AV_CODEC_ID_VC1IMAGE:
95     case AV_CODEC_ID_WMV3IMAGE:
96     case AV_CODEC_ID_MSS2:
97         s->h263_pred = 1;
98         s->msmpeg4_version=6;
99         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
100         break;
101     case AV_CODEC_ID_H263I:
102         break;
103     case AV_CODEC_ID_FLV1:
104         s->h263_flv = 1;
105         break;
106     default:
107         return -1;
108     }
109     s->codec_id= avctx->codec->id;
110     avctx->hwaccel= ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
111
112     /* for h263, we allocate the images after having read the header */
113     if (avctx->codec->id != AV_CODEC_ID_H263 && avctx->codec->id != AV_CODEC_ID_MPEG4)
114         if (ff_MPV_common_init(s) < 0)
115             return -1;
116
117         ff_h263_decode_init_vlc();
118
119     return 0;
120 }
121
122 av_cold int ff_h263_decode_end(AVCodecContext *avctx)
123 {
124     MpegEncContext *s = avctx->priv_data;
125
126     ff_MPV_common_end(s);
127     return 0;
128 }
129
130 /**
131  * Return the number of bytes consumed for building the current frame.
132  */
133 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
134     int pos= (get_bits_count(&s->gb)+7)>>3;
135
136     if(s->divx_packed || s->avctx->hwaccel){
137         //we would have to scan through the whole buf to handle the weird reordering ...
138         return buf_size;
139     }else if(s->flags&CODEC_FLAG_TRUNCATED){
140         pos -= s->parse_context.last_index;
141         if(pos<0) pos=0; // padding is not really read so this might be -1
142         return pos;
143     }else{
144         if(pos==0) pos=1; //avoid infinite loops (i doubt that is needed but ...)
145         if(pos+10>buf_size) pos=buf_size; // oops ;)
146
147         return pos;
148     }
149 }
150
151 static int decode_slice(MpegEncContext *s){
152     const int part_mask= s->partitioned_frame ? (ER_AC_END|ER_AC_ERROR) : 0x7F;
153     const int mb_size = 16;
154     s->last_resync_gb= s->gb;
155     s->first_slice_line= 1;
156
157     s->resync_mb_x= s->mb_x;
158     s->resync_mb_y= s->mb_y;
159
160     ff_set_qscale(s, s->qscale);
161
162     if (s->avctx->hwaccel) {
163         const uint8_t *start= s->gb.buffer + get_bits_count(&s->gb)/8;
164         const uint8_t *end  = ff_h263_find_resync_marker(start + 1, s->gb.buffer_end);
165         skip_bits_long(&s->gb, 8*(end - start));
166         return s->avctx->hwaccel->decode_slice(s->avctx, start, end - start);
167     }
168
169     if(s->partitioned_frame){
170         const int qscale= s->qscale;
171
172         if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4){
173             if(ff_mpeg4_decode_partitions(s) < 0)
174                 return -1;
175         }
176
177         /* restore variables which were modified */
178         s->first_slice_line=1;
179         s->mb_x= s->resync_mb_x;
180         s->mb_y= s->resync_mb_y;
181         ff_set_qscale(s, qscale);
182     }
183
184     for(; s->mb_y < s->mb_height; s->mb_y++) {
185         /* per-row end of slice checks */
186         if(s->msmpeg4_version){
187             if(s->resync_mb_y + s->slice_height == s->mb_y){
188                 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_MB_END);
189
190                 return 0;
191             }
192         }
193
194         if(s->msmpeg4_version==1){
195             s->last_dc[0]=
196             s->last_dc[1]=
197             s->last_dc[2]= 128;
198         }
199
200         ff_init_block_index(s);
201         for(; s->mb_x < s->mb_width; s->mb_x++) {
202             int ret;
203
204             ff_update_block_index(s);
205
206             if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
207                 s->first_slice_line=0;
208             }
209
210             /* DCT & quantize */
211
212             s->mv_dir = MV_DIR_FORWARD;
213             s->mv_type = MV_TYPE_16X16;
214 //            s->mb_skipped = 0;
215             av_dlog(s, "%d %d %06X\n",
216                     ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
217             ret= s->decode_mb(s, s->block);
218
219             if (s->pict_type!=AV_PICTURE_TYPE_B)
220                 ff_h263_update_motion_val(s);
221
222             if(ret<0){
223                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
224                 if(ret==SLICE_END){
225                     ff_MPV_decode_mb(s, s->block);
226                     if(s->loop_filter)
227                         ff_h263_loop_filter(s);
228
229                     ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_MB_END&part_mask);
230
231                     s->padding_bug_score--;
232
233                     if(++s->mb_x >= s->mb_width){
234                         s->mb_x=0;
235                         ff_mpeg_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
236                         ff_MPV_report_decode_progress(s);
237                         s->mb_y++;
238                     }
239                     return 0;
240                 }else if(ret==SLICE_NOEND){
241                     av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
242                     ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x+1, s->mb_y, ER_MB_END&part_mask);
243                     return -1;
244                 }
245                 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
246                 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_MB_ERROR&part_mask);
247
248                 return -1;
249             }
250
251             ff_MPV_decode_mb(s, s->block);
252             if(s->loop_filter)
253                 ff_h263_loop_filter(s);
254         }
255
256         ff_mpeg_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
257         ff_MPV_report_decode_progress(s);
258
259         s->mb_x= 0;
260     }
261
262     assert(s->mb_x==0 && s->mb_y==s->mb_height);
263
264     if(s->codec_id==AV_CODEC_ID_MPEG4
265        && (s->workaround_bugs&FF_BUG_AUTODETECT)
266        && get_bits_left(&s->gb) >= 48
267        && show_bits(&s->gb, 24)==0x4010
268        && !s->data_partitioning)
269         s->padding_bug_score+=32;
270
271     /* try to detect the padding bug */
272     if(      s->codec_id==AV_CODEC_ID_MPEG4
273        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
274        &&    get_bits_left(&s->gb) >=0
275        &&    get_bits_left(&s->gb) < 48
276 //       &&   !s->resync_marker
277        &&   !s->data_partitioning){
278
279         const int bits_count= get_bits_count(&s->gb);
280         const int bits_left = s->gb.size_in_bits - bits_count;
281
282         if(bits_left==0){
283             s->padding_bug_score+=16;
284         } else if(bits_left != 1){
285             int v= show_bits(&s->gb, 8);
286             v|= 0x7F >> (7-(bits_count&7));
287
288             if(v==0x7F && bits_left<=8)
289                 s->padding_bug_score--;
290             else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
291                 s->padding_bug_score+= 4;
292             else
293                 s->padding_bug_score++;
294         }
295     }
296
297     if(s->workaround_bugs&FF_BUG_AUTODETECT){
298         if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version>=0 || !s->resync_marker)*/)
299             s->workaround_bugs |=  FF_BUG_NO_PADDING;
300         else
301             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
302     }
303
304     // handle formats which don't have unique end markers
305     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
306         int left= get_bits_left(&s->gb);
307         int max_extra=7;
308
309         /* no markers in M$ crap */
310         if(s->msmpeg4_version && s->pict_type==AV_PICTURE_TYPE_I)
311             max_extra+= 17;
312
313         /* buggy padding but the frame should still end approximately at the bitstream end */
314         if((s->workaround_bugs&FF_BUG_NO_PADDING) && (s->err_recognition&AV_EF_BUFFER))
315             max_extra+= 48;
316         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
317             max_extra+= 256*256*256*64;
318
319         if(left>max_extra){
320             av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
321         }
322         else if(left<0){
323             av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
324         }else
325             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_MB_END);
326
327         return 0;
328     }
329
330     av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
331             get_bits_left(&s->gb),
332             show_bits(&s->gb, 24), s->padding_bug_score);
333
334     ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_MB_END&part_mask);
335
336     return -1;
337 }
338
339 int ff_h263_decode_frame(AVCodecContext *avctx,
340                              void *data, int *got_frame,
341                              AVPacket *avpkt)
342 {
343     const uint8_t *buf = avpkt->data;
344     int buf_size = avpkt->size;
345     MpegEncContext *s = avctx->priv_data;
346     int ret;
347     AVFrame *pict = data;
348
349     s->flags= avctx->flags;
350     s->flags2= avctx->flags2;
351
352     /* no supplementary picture */
353     if (buf_size == 0) {
354         /* special case for last picture */
355         if (s->low_delay==0 && s->next_picture_ptr) {
356             if ((ret = av_frame_ref(pict, &s->next_picture_ptr->f)) < 0)
357                 return ret;
358             s->next_picture_ptr= NULL;
359
360             *got_frame = 1;
361         }
362
363         return 0;
364     }
365
366     if(s->flags&CODEC_FLAG_TRUNCATED){
367         int next;
368
369         if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4){
370             next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
371         }else if(CONFIG_H263_DECODER && s->codec_id==AV_CODEC_ID_H263){
372             next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
373         }else{
374             av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
375             return -1;
376         }
377
378         if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
379             return buf_size;
380     }
381
382
383 retry:
384
385     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
386         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
387     }else
388         init_get_bits(&s->gb, buf, buf_size*8);
389     s->bitstream_buffer_size=0;
390
391     if (!s->context_initialized) {
392         if (ff_MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
393             return -1;
394     }
395
396     /* We need to set current_picture_ptr before reading the header,
397      * otherwise we cannot store anyting in there */
398     if (s->current_picture_ptr == NULL || s->current_picture_ptr->f.data[0]) {
399         int i= ff_find_unused_picture(s, 0);
400         if (i < 0)
401             return i;
402         s->current_picture_ptr= &s->picture[i];
403     }
404
405     /* let's go :-) */
406     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5) {
407         ret= ff_wmv2_decode_picture_header(s);
408     } else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {
409         ret = ff_msmpeg4_decode_picture_header(s);
410     } else if (CONFIG_MPEG4_DECODER && s->h263_pred) {
411         if(s->avctx->extradata_size && s->picture_number==0){
412             GetBitContext gb;
413
414             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
415             ret = ff_mpeg4_decode_picture_header(s, &gb);
416         }
417         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
418     } else if (CONFIG_H263I_DECODER && s->codec_id == AV_CODEC_ID_H263I) {
419         ret = ff_intel_h263_decode_picture_header(s);
420     } else if (CONFIG_FLV_DECODER && s->h263_flv) {
421         ret = ff_flv_decode_picture_header(s);
422     } else {
423         ret = ff_h263_decode_picture_header(s);
424     }
425
426     if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
427
428     /* skip if the header was thrashed */
429     if (ret < 0){
430         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
431         return -1;
432     }
433
434     avctx->has_b_frames= !s->low_delay;
435
436     if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
437         if(s->stream_codec_tag == AV_RL32("XVID") ||
438            s->codec_tag == AV_RL32("XVID") || s->codec_tag == AV_RL32("XVIX") ||
439            s->codec_tag == AV_RL32("RMP4") || s->codec_tag == AV_RL32("ZMP4") ||
440            s->codec_tag == AV_RL32("SIPP")
441            )
442             s->xvid_build= 0;
443 #if 0
444         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
445            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
446             s->xvid_build= 0;
447 #endif
448     }
449
450     if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
451         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
452             s->divx_version= 400; //divx 4
453     }
454
455     if(s->xvid_build>=0 && s->divx_version>=0){
456         s->divx_version=
457         s->divx_build= -1;
458     }
459
460     if(s->workaround_bugs&FF_BUG_AUTODETECT){
461         if(s->codec_tag == AV_RL32("XVIX"))
462             s->workaround_bugs|= FF_BUG_XVID_ILACE;
463
464         if(s->codec_tag == AV_RL32("UMP4")){
465             s->workaround_bugs|= FF_BUG_UMP4;
466         }
467
468         if(s->divx_version>=500 && s->divx_build<1814){
469             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
470         }
471
472         if(s->divx_version>502 && s->divx_build<1814){
473             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
474         }
475
476         if(s->xvid_build<=3U)
477             s->padding_bug_score= 256*256*256*64;
478
479         if(s->xvid_build<=1U)
480             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
481
482         if(s->xvid_build<=12U)
483             s->workaround_bugs|= FF_BUG_EDGE;
484
485         if(s->xvid_build<=32U)
486             s->workaround_bugs|= FF_BUG_DC_CLIP;
487
488 #define SET_QPEL_FUNC(postfix1, postfix2) \
489     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
490     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
491     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
492
493         if(s->lavc_build<4653U)
494             s->workaround_bugs|= FF_BUG_STD_QPEL;
495
496         if(s->lavc_build<4655U)
497             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
498
499         if(s->lavc_build<4670U){
500             s->workaround_bugs|= FF_BUG_EDGE;
501         }
502
503         if(s->lavc_build<=4712U)
504             s->workaround_bugs|= FF_BUG_DC_CLIP;
505
506         if(s->divx_version>=0)
507             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
508         if(s->divx_version==501 && s->divx_build==20020416)
509             s->padding_bug_score= 256*256*256*64;
510
511         if(s->divx_version<500U){
512             s->workaround_bugs|= FF_BUG_EDGE;
513         }
514
515         if(s->divx_version>=0)
516             s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
517 #if 0
518         if(s->divx_version==500)
519             s->padding_bug_score= 256*256*256*64;
520
521         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
522          * Let us hope this at least works.
523          */
524         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==-1
525            && s->codec_id==AV_CODEC_ID_MPEG4 && s->vo_type==0)
526             s->workaround_bugs|= FF_BUG_NO_PADDING;
527
528         if(s->lavc_build<4609U) //FIXME not sure about the version num but a 4609 file seems ok
529             s->workaround_bugs|= FF_BUG_NO_PADDING;
530 #endif
531     }
532
533     if(s->workaround_bugs& FF_BUG_STD_QPEL){
534         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
535         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
536         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
537         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
538         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
539         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
540
541         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
542         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
543         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
544         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
545         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
546         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
547     }
548
549     if(avctx->debug & FF_DEBUG_BUGS)
550         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
551                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
552                s->divx_packed ? "p" : "");
553
554 #if HAVE_MMX
555     if (s->codec_id == AV_CODEC_ID_MPEG4 && s->xvid_build>=0 && avctx->idct_algo == FF_IDCT_AUTO && (av_get_cpu_flags() & AV_CPU_FLAG_MMX)) {
556         avctx->idct_algo= FF_IDCT_XVIDMMX;
557         ff_dct_common_init(s);
558         s->picture_number=0;
559     }
560 #endif
561
562         /* After H263 & mpeg4 header decode we have the height, width,*/
563         /* and other parameters. So then we could init the picture   */
564         /* FIXME: By the way H263 decoder is evolving it should have */
565         /* an H263EncContext                                         */
566
567     if (!avctx->coded_width || !avctx->coded_height) {
568         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
569
570         s->parse_context.buffer=0;
571         ff_MPV_common_end(s);
572         s->parse_context= pc;
573         avcodec_set_dimensions(avctx, s->width, s->height);
574
575         goto retry;
576     }
577
578     if (s->width  != avctx->coded_width  ||
579         s->height != avctx->coded_height ||
580         s->context_reinit) {
581         /* H.263 could change picture size any time */
582         s->context_reinit = 0;
583
584         avcodec_set_dimensions(avctx, s->width, s->height);
585
586         if ((ret = ff_MPV_common_frame_size_change(s)))
587             return ret;
588     }
589
590     if((s->codec_id==AV_CODEC_ID_H263 || s->codec_id==AV_CODEC_ID_H263P || s->codec_id == AV_CODEC_ID_H263I))
591         s->gob_index = ff_h263_get_gob_height(s);
592
593     // for skipping the frame
594     s->current_picture.f.pict_type = s->pict_type;
595     s->current_picture.f.key_frame = s->pict_type == AV_PICTURE_TYPE_I;
596
597     /* skip B-frames if we don't have reference frames */
598     if (s->last_picture_ptr == NULL &&
599         (s->pict_type == AV_PICTURE_TYPE_B || s->droppable))
600         return get_consumed_bytes(s, buf_size);
601     if(   (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==AV_PICTURE_TYPE_B)
602        || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=AV_PICTURE_TYPE_I)
603        ||  avctx->skip_frame >= AVDISCARD_ALL)
604         return get_consumed_bytes(s, buf_size);
605
606     if(s->next_p_frame_damaged){
607         if(s->pict_type==AV_PICTURE_TYPE_B)
608             return get_consumed_bytes(s, buf_size);
609         else
610             s->next_p_frame_damaged=0;
611     }
612
613     if((!s->no_rounding) || s->pict_type==AV_PICTURE_TYPE_B){
614         s->me.qpel_put= s->dsp.put_qpel_pixels_tab;
615         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
616     }else{
617         s->me.qpel_put= s->dsp.put_no_rnd_qpel_pixels_tab;
618         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
619     }
620
621     if(ff_MPV_frame_start(s, avctx) < 0)
622         return -1;
623
624     if (!s->divx_packed && !avctx->hwaccel)
625         ff_thread_finish_setup(avctx);
626
627     if (CONFIG_MPEG4_VDPAU_DECODER && (s->avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU)) {
628         ff_vdpau_mpeg4_decode_picture(s, s->gb.buffer, s->gb.buffer_end - s->gb.buffer);
629         goto frame_end;
630     }
631
632     if (avctx->hwaccel) {
633         if (avctx->hwaccel->start_frame(avctx, s->gb.buffer, s->gb.buffer_end - s->gb.buffer) < 0)
634             return -1;
635     }
636
637     ff_mpeg_er_frame_start(s);
638
639     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
640     //which is not available before ff_MPV_frame_start()
641     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5){
642         ret = ff_wmv2_decode_secondary_picture_header(s);
643         if(ret<0) return ret;
644         if(ret==1) goto intrax8_decoded;
645     }
646
647     /* decode each macroblock */
648     s->mb_x=0;
649     s->mb_y=0;
650
651     ret = decode_slice(s);
652     while(s->mb_y<s->mb_height){
653         if(s->msmpeg4_version){
654             if(s->slice_height==0 || s->mb_x!=0 || (s->mb_y%s->slice_height)!=0 || get_bits_left(&s->gb)<0)
655                 break;
656         }else{
657             int prev_x=s->mb_x, prev_y=s->mb_y;
658             if(ff_h263_resync(s)<0)
659                 break;
660             if (prev_y * s->mb_width + prev_x < s->mb_y * s->mb_width + s->mb_x)
661                 s->er.error_occurred = 1;
662         }
663
664         if(s->msmpeg4_version<4 && s->h263_pred)
665             ff_mpeg4_clean_buffers(s);
666
667         if (decode_slice(s) < 0) ret = AVERROR_INVALIDDATA;
668     }
669
670     if (s->msmpeg4_version && s->msmpeg4_version<4 && s->pict_type==AV_PICTURE_TYPE_I)
671         if(!CONFIG_MSMPEG4_DECODER || ff_msmpeg4_decode_ext_header(s, buf_size) < 0){
672             s->er.error_status_table[s->mb_num - 1] = ER_MB_ERROR;
673         }
674
675     assert(s->bitstream_buffer_size==0);
676 frame_end:
677     /* divx 5.01+ bistream reorder stuff */
678     if(s->codec_id==AV_CODEC_ID_MPEG4 && s->divx_packed){
679         int current_pos= get_bits_count(&s->gb)>>3;
680         int startcode_found=0;
681
682         if(buf_size - current_pos > 5){
683             int i;
684             for(i=current_pos; i<buf_size-3; i++){
685                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
686                     startcode_found=1;
687                     break;
688                 }
689             }
690         }
691         if(s->gb.buffer == s->bitstream_buffer && buf_size>7 && s->xvid_build>=0){ //xvid style
692             startcode_found=1;
693             current_pos=0;
694         }
695
696         if(startcode_found){
697             av_fast_malloc(
698                 &s->bitstream_buffer,
699                 &s->allocated_bitstream_buffer_size,
700                 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
701             if (!s->bitstream_buffer)
702                 return AVERROR(ENOMEM);
703             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
704             s->bitstream_buffer_size= buf_size - current_pos;
705         }
706     }
707
708 intrax8_decoded:
709     ff_er_frame_end(&s->er);
710
711     if (avctx->hwaccel) {
712         if (avctx->hwaccel->end_frame(avctx) < 0)
713             return -1;
714     }
715
716     ff_MPV_frame_end(s);
717
718     if (!s->divx_packed && avctx->hwaccel)
719         ff_thread_finish_setup(avctx);
720
721     assert(s->current_picture.f.pict_type == s->current_picture_ptr->f.pict_type);
722     assert(s->current_picture.f.pict_type == s->pict_type);
723     if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
724         if ((ret = av_frame_ref(pict, &s->current_picture_ptr->f)) < 0)
725             return ret;
726         ff_print_debug_info(s, s->current_picture_ptr);
727     } else if (s->last_picture_ptr != NULL) {
728         if ((ret = av_frame_ref(pict, &s->last_picture_ptr->f)) < 0)
729             return ret;
730         ff_print_debug_info(s, s->last_picture_ptr);
731     }
732
733     if(s->last_picture_ptr || s->low_delay){
734         *got_frame = 1;
735     }
736
737     return (ret && (avctx->err_recognition & AV_EF_EXPLODE))?ret:get_consumed_bytes(s, buf_size);
738 }
739
740 const enum AVPixelFormat ff_h263_hwaccel_pixfmt_list_420[] = {
741 #if CONFIG_VAAPI
742     AV_PIX_FMT_VAAPI_VLD,
743 #endif
744 #if CONFIG_VDPAU
745     AV_PIX_FMT_VDPAU,
746 #endif
747     AV_PIX_FMT_YUV420P,
748     AV_PIX_FMT_NONE
749 };
750
751 AVCodec ff_h263_decoder = {
752     .name           = "h263",
753     .type           = AVMEDIA_TYPE_VIDEO,
754     .id             = AV_CODEC_ID_H263,
755     .priv_data_size = sizeof(MpegEncContext),
756     .init           = ff_h263_decode_init,
757     .close          = ff_h263_decode_end,
758     .decode         = ff_h263_decode_frame,
759     .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
760                       CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
761     .flush          = ff_mpeg_flush,
762     .long_name      = NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
763     .pix_fmts       = ff_h263_hwaccel_pixfmt_list_420,
764 };